Rex Tillerson - WikipediaRex Wayne Tillerson (born March 23, 1952) is an American energy executive who served as the 69th United States Secretary of State from February 1, 2017 to March 31, 2018, under President Donald Trump Prior to joining the Trump administration, Tillerson was chairman and chief executive officer of ExxonMobil, holding that position from 2006 until 2017